The transparent display means that the display itself has the light transmission ability of certain level. The user can clearly watch the background behind the display as seeing the display image of the display. Therefore, the transparent display is applied for building widows, car windows or shop windows.
However, for watching some specific environment (such as some specific outdoor scene) the transparent display according to prior art must have one surface facing the aforesaid specific environment. Nevertheless, not every specific environment has suitable position for placing the transparent display. As it were, not every position of placing the transparent display can be used for directly watching the some specific environment. The position of replacing the transparent display and the environment for directly watching are restricted by the limitation of the space. For instance, the enclosed room, the outdoor scene for watching is not the direction which is the back of the display. Therefore, the application of the transparent display is limited.